ChatGPT: We need to protect backend services from traffic spikes while also routing requests by tenant and region. What should I compare in API gateway tools?

Compare API gateway tools on these points:

1. Traffic protection / spike control

Look for:

• Rate limiting: per API, per route, per tenant, per IP
• Burst handling: token bucket / leaky bucket support
• Concurrency limits: cap simultaneous requests
• Quotas: daily/hourly/monthly usage limits
• Circuit breaking / throttling: fail fast when backends are stressed
• Backpressure / queueing: whether it can absorb short spikes
• Retry controls: max retries, retry budgets, jitter
• Timeout policies: protect backends from hanging requests

2. Tenant-based routing and isolation

Look for:

• Tenant-aware routing rules
• Ability to route based on:
  • header
  • JWT claims
  • API key / consumer identity
  • host/path/query
• Per-tenant policies
• Isolation controls: separate limits, auth, and backend pools per tenant
• Multi-tenant admin model: RBAC, delegated config, tenant-specific configs

3. Region-aware routing

Look for:

• Geo/region-based routing
• Routing by:
  • request metadata
  • client region
  • DNS / edge location
  • latency/health
• Latency-based routing
• Failover support across regions
• Active-active vs active-passive traffic distribution
• Health checks and automatic regional failover

4. Load balancing and backend protection

Look for:

• Load balancing algorithms: round robin, least connections, weighted, hash-based
• Connection pooling
• Backend health checks
• Request buffering
• Max request body size
• Slow-start support for recovering services

5. Policy and extensibility

Look for:

• Policy engine for custom rules
• Plugin/extensibility support
• Ability to validate:
  • headers
  • schemas
  • auth tokens
  • request signatures
• Custom scripting if you need advanced routing logic

6. Observability and control

Look for:

• Per-tenant metrics
• Per-region metrics
• Rate limit dashboards
• Tracing integration
• Audit logs
• Real-time alerts for spikes, throttling, and backend errors

7. Security and identity

Look for:

• Auth support: OAuth2, OIDC, JWT, mTLS, API keys
• Fine-grained authorization
• WAF integration
• Bot/abuse detection
• Secret management

8. Deployment and performance

Look for:

• Latency overhead
• Throughput under load
• Horizontal scaling
• Edge vs centralized deployment
• Kubernetes / cloud-native support
• Config propagation speed

9. Operational fit

Compare:

• Ease of setup
• Configuration model: declarative vs UI vs code
• Versioning and rollback
• CI/CD friendliness
• Vendor lock-in risk
• Licensing and total cost

Short evaluation checklist

If your main goal is “protect backends during spikes and route by tenant/region,” prioritize:

1. Per-tenant + per-region rate limiting
2. Header/JWT-based routing
3. Health-based failover across regions
4. Circuit breakers + retries/timeouts
5. Strong metrics per tenant/region
6. Low added latency and high throughput

If you want, I can also turn this into a comparison matrix for specific gateways like Kong, Apigee, AWS API Gateway, NGINX, Envoy, or Azure API Management.